Abstract: To solve the problems of existing provable data possession (PDP) protocols only applicable to single cloud storage servers and over-reliance on public key infrastructure, a new identity-based multi-cloud multi-replica PDP protocol is proposed. This protocol adopts identity encryption to simplify certificate management, and designs a double-layer Merkle hash tree as a new secure data structure to maintain the freshness and consistency of multi-replica. Security analysis and experimental results verify the security and efficiency of this protocol, which can achieve multi-replica integrity auditing on multiple cloud storage servers, and significantly outperform the efficiency of comparison algorithms in the three stages of tag generation, evidence generation, and evidence verification.

Key words: cloud storage, data integrity auditing, multi-cloud servers, multi-copy, identity encryption